The present invention deals with a power machine. More specifically, the present invention deals with a power machine having an attachment with a control device for controlling the attachment.
Power machines, such as skid steer loaders, typically have a frame which supports a cab or an operator compartment and a movable lift arm which, in turn, supports a work tool such as a bucket, an auger, a tree spade, or other work tool. The movable lift arm is pivotally coupled to the frame of the skid steer loader and is powered by power actuators which are commonly hydraulic cylinders. In addition, the tool is coupled to the lift arm and is powered by one or more additional power actuators which are also commonly hydraulic cylinders. An operator manipulating a skid steer loader raises and lowers the lift arm, and manipulates the tool, by actuating the hydraulic cylinders coupled to the lift arm, and the hydraulic cylinders coupled to the tool.
With a front attachment (or tool) such as a tree spade, cement mixer, etc., which utilizes one or more hydraulic actuators, a number of valves must typically be added to the hydraulic system of the skid steer loader in order to control the flow of hydraulic fluid under pressure to the plurality of cylinders on the attachment. In the past, the addition of these valves has required the addition of mounting hardware on the skid steer loader. For example, in some prior skid steer loaders, the valve bank used to control the hydraulic actuators on the attachment was mounted on the doorway of the cab or operator compartment. This required the hydraulic fluid under pressure to be routed to that valve bank, and then out to the attachment.
It is also common for control levers in skid steer loaders to have hand grips which support a plurality of buttons or actuable switches, actuable by the operator to perform certain functions. Depending on the particular type of attachment or attachments mounted on the skid steer loader, certain functions may be disabled or unusable. Further, depending on the particular type of attachment or attachments mounted on the skid steer loader, certain combinations of inputs from the operator input devices, when performed simultaneously, can result in opposing control valves being opened. This essentially provides an equal amount of pressurized fluid to both sides of a hydraulic actuator or hydraulic motor.